workflows/release-binaries: Stop using ccache (llvm#124415)

Using ccache relies on the GitHub Actions Cache, which may be
susceptible to cache poisoning. See
https://adnanthekhan.com/2024/05/06/the-monsters-in-your-build-cache-github-actions-cache-poisoning/

Even though these attacks may be difficult, it's better to err on the
side of caution and ensure that the build environment for our releases
is as isolated as possible. Additionally, ccache was only being used for
the stage1 build, which is a small part of the overall build, so the
speed up from using it was not that large.

Author: tstellar

.github/workflows/release-binaries.yml

@@ -226,14 +226,6 @@ jobs:
       id: setup-stage
       uses: ./workflows-main/.github/workflows/release-binaries-setup-stage
 
-    - name: Setup sccache
-      uses: hendrikmuhs/ccache-action@ca3acd2731eef11f1572ccb126356c2f9298d35e # v1.2.9
-      with:
-        # Default to 2G to workaround: https://github.com/hendrikmuhs/ccache-action/issues/174
-        max-size: 2G
-        key: ${{ needs.prepare.outputs.ccache }}-${{ runner.os }}-${{ runner.arch }}-release
-        variant: ${{ needs.prepare.outputs.ccache }}
-
     - name: Configure
       id: build
       shell: bash
@@ -246,9 +238,8 @@ jobs:
             ${{ needs.prepare.outputs.target-cmake-flags }} \
             -C clang/cmake/caches/Release.cmake \
             -DBOOTSTRAP_LLVM_PARALLEL_LINK_JOBS=1 \
-            -DBOOTSTRAP_CPACK_PACKAGE_FILE_NAME="${{ needs.prepare.outputs.release-binary-basename }}" \
-            -DCMAKE_C_COMPILER_LAUNCHER=$CCACHE_BIN \
-            -DCMAKE_CXX_COMPILER_LAUNCHER=$CCACHE_BIN
+            -DBOOTSTRAP_CPACK_PACKAGE_FILE_NAME="${{ needs.prepare.outputs.release-binary-basename }}"
+
     - name: Build
       shell: bash
       run: |